NEW YORK -- John Mack, in his first move as chief executive of Wall Street's Credit Suisse First Boston, hired a well-known lawyer versed in various matters from corporate-finance work to regulatory issues.

Stephen Volk, 65 years old, is a former senior partner of Shearman & Sterling, a large law firm that caters to major corporations. He will join CSFB as a vice chairman and member of its executive board effective Aug.&nbsp;1.